Which best defines an operating system (OS)?

	a.	It is a computer and all the software for managing network resources and offering services to a network.
	b.	It is a collection of disk drives used for fault tolerance and is typically found in large network systems.
	c.	It is a set of programs for controlling and managing computer hardware and software.
	d.	It is the main circuit board containing connectors for attaching additional boards.

With Voice over Internet Protocol (VoIP), _____.

	a.	users can have calls forwarded from anywhere in the world
	b.	call quality is significantly better than that of regular phone lines
	c.	users cannot screen callers if the caller has caller ID blocked
	d.	voicemails cannot be received on the computer